Going off purely what Bush and Obama spoke about here (there is several years worth of discussion and dissection of both men's terms in office, it doesn't need to be compounded here), I agree. Wholeheartedly. Nothing neither of them said is wrong. They're both scathing, in their own mannerisms, and seek to compound a multi-faceted attack on Trump and his brand of politics. It's nothing short of a miracle that, assuming there wasn't correspondence between the two, that they'd stay so in sync with branding Trump 'cruel'.
Do I think this will make any real difference? Not sure, and I'll lean on being pessimistic since this is notedly a rare occurrence for Bush, and somewhat of one for Obama. If they, and several previous leaders (because let's be honest, do we know any who actively like Trump?) were to keep this up over the next year, maybe it'll be an abscess in the stomach of Trump's next election campaign, along with every other self-inflicted cultural and political ailment he's picked up over this past year.
Obama keyed in the most important part, the Virginia election will be telling if any and all public and political outcry has done anything to rattle the echo-chamber that is Trump's voter base.